End-to-end encryption is a requirement for secure communication. Anything less is the same as scribbling on paper and tossing it to the recipient, and hoping nobody catches it on the way.
To take it a step further, end to end encryption is only good when you can protect your private key and passphrase... All you have to do is take a look at Rakshasha (https://www.youtube.com/watch?v=yRpilXPv8pU) for a practical example of how compromised we all really are.
For example, if you want to convince someone to become a vegan, which path is more likely to succeed:
Omnivore => Vegan
Omnivore => Vegetarian => Vegan
Omnivore => No red meat => Only fish => Vegetarian => VeganD(Omnivore => Vegan) > D(Omnivore => No red meat) + D(No red meat => Only fish) + D(Only fish => Vegetarian) + D(Vegetarian => Vegan)
Often intermediate steps are significantly easier to implement than just implementing the end result. It's the same reason for which people tend to break big scary tasks into sequence of many easier ones.
They hadn't thought about the ethics of meat before, when they did, they chose to be vegan.
So it turns out (in my experience) telling rational people "do the thing that makes sense, even if it's a little extreme" is much more likely to result in the most extreme change of behavior. But we're deep into anecdotal/psychological theory land here, so I claim no authority beyond N=30 vegans.